I have a new build house which has a Vortice extractor fan correctly wired up via an isolator, however I wish to fit an LED bathroom cabinet directly below it, the cable to the fan is 4 wire .Brown, Blue, Grey and bare copper (Earth I presume). of which only 2 are connected (Brown and Blue)
I'm told casually by an electrician that I can power the cabinet by extending the unused GREY wire to the block within the cabinet he didn't say if I needed to carry the other 3 wires over as well.
I suspect I needn't carry over the Brown wire just the Blue and Earth as the Grey would be taking Browns place but I thought it's better to get a Pros opinion before I start connecting up. Your advice would be most appreciated.
Cheers.
Pete